Increase maximum message size to 64 KB.
Increase maximum message size to 64 KB.

Testing obfs3-in-websocket was reliably failing at 50% bootstrapped with
a message of about 30 KB.

arlolra/flashproxy,infinity0/flashproxy,glamrock/flashproxy,arlolra/flashproxy,glamrock/flashproxy,glamrock/flashproxy,glamrock/flashproxy,infinity0/flashproxy,glamrock/flashproxy,glamrock/flashproxy,infinity0/flashproxy,arlolra/flashproxy,infinity0/flashproxy,infinity0/flashproxy,arlolra/flashproxy,arlolra/flashproxy,infinity0/flashproxy,arlolra/flashproxy,arlolra/flashproxy